As personal mobile devices have become nearly ubiquitous, users have come to rely on them for many details of their lives. Many such devices are location-aware, meaning that they are able to determine and report their locations to service providers. This allows the service providers to customize information provided to particular users based on the locations of those users. For example, when a user is looking for a restaurant, a service can provide information about restaurants that are nearby the user. Advertising and other types of messaging can also be provided based on location.
However, it can be difficult to select appropriately targeted advertising and other content based solely on location. Additional methods of determining user interests would therefore be valuable to advertising, messaging, and notification providers.